Alphabetize Names within Single row on Multiple rows

Trying to alphabetize names in a single row separated by ";" I have long lists of names occupying single cells, example: 'Anne Ferguson; Allen Neale; Robert Gilday; Joseph McMilleon; James Kelcourse; Derek Kimball; Christian Scorzoni; Robert Lavoie; Donna McClure'. The format is correct and they all need to be in a single cell but I need them to be alphabetized as they are currently not. Example:

DEMO SET (Original)
Michael Franey; Kevin Donovan; Thomas Dion, III; R. Andrew Burbine; Kenneth Coyle
Pamela Harting-Barrat; Janet Adachi; David Clough; Michael Gowing; John Sonner
David Wojnar; Kevin Gaspar; Leslie Dakin
Paula Melville; Arthur Harrington; Michael Ouellette; John E. Duval; Scott Nichols
Dennis Perry; Robert Rossi; Christopher Johnson; Anthony Suffriti; Cecilia Calabrese; Paul Cavallo; James Cichetti; Gina Letellier; George Bitzas; Joseph Mineo; Donald Rheault
Raymond Wilcox; Charles Ketchen

DEMO SET (Desired Output)
R. Andrew Burbine; Kenneth Coyle; Thomas Dion, III; Kevin Donovan; Michael Franey
Janet Adachi; David Clough; Michael Gowing; Pamela Harting-Barrat; John Sonner
Leslie Dakin; Kevin Gaspar; David Wojnar
John E. Duval; Arthur Harrington; Paula Melville; Scott Nichols; Michael Ouellette
George Bitzas; Cecilia Calabrese; Paul Cavallo; James Cichetti; Christopher Johnson; Gina Letellier; Joseph Mineo; Dennis Perry; Donald Rheault; Robert Rossi; Anthony Suffriti
Charles Ketchen; Raymond Wilcox

I have 4 spreadsheets with 351 rows of data like that each, I can't mix them up so I need to do this for all 351 rows in each spreadsheet. Reorganizing all 1400+ cells alphabetically by hand would take longer than I can work on this so any way to automate it? I'm using Excel 2011, Mac version. Thanks!